A patient taking a thiazide diuretic reports muscle cramps.
What should the nurse do?

Choice A rationale

Dehydration is not a primary complication directly associated with beta-blocker use. Beta-blockers, such as propranolol or metoprolol, primarily affect the cardiovascular system by blocking beta-adrenergic receptors, which decreases heart rate and blood pressure. Dehydration is typically caused by inadequate fluid intake or excessive fluid loss from conditions like vomiting, diarrhea, or diuresis.

Choice B rationale

Hyperkalemia is an elevated potassium level, which is a rare side effect of non-selective beta-blockers, but not a primary complication to monitor for in a patient taking a beta-blocker for hypertension. Hyperkalemia is more commonly associated with conditions like renal failure or the use of certain medications, such as ACE inhibitors or potassium-sparing diuretics.

Choice C rationale

Beta-blockers can mask the physiological signs of hypoglycemia in patients with diabetes, such as tremors, palpitations, and tachycardia. This occurs because the drugs block the sympathetic nervous system's compensatory response to low blood glucose, which normally involves the release of epinephrine. Consequently, a patient may not recognize a hypoglycemic event until it becomes severe.

Choice D rationale

Angina is a symptom of myocardial ischemia, and beta-blockers are often used to prevent it, not cause it. By reducing the heart rate and contractility, beta-blockers decrease myocardial oxygen demand. This effect helps to prevent chest pain associated with angina, making it a therapeutic benefit rather than a potential complication.

Choice A rationale

Furosemide is a loop diuretic that inhibits the reabsorption of sodium and chloride in the thick ascending limb of the loop of Henle. This action increases the excretion of these ions, as well as potassium, through the kidneys. The increased urinary potassium loss can lead to hypokalemia, a common and potentially dangerous side effect requiring careful monitoring of serum potassium levels (normal range 3.5-5.0 mEq/L).

Choice B rationale

Spironolactone is a potassium-sparing diuretic that acts as a competitive antagonist of aldosterone in the distal convoluted tubule and collecting duct. By blocking aldosterone's effects, it promotes the excretion of sodium and water while promoting the reabsorption of potassium. This mechanism increases serum potassium levels, and therefore, this medication is more likely to cause hyperkalemia, not hypokalemia.

Choice C rationale

Lisinopril is an ACE inhibitor (angiotensin-converting enzyme inhibitor). It blocks the conversion of angiotensin I to angiotensin II, leading to decreased aldosterone secretion. Decreased aldosterone reduces the retention of sodium and water and the excretion of potassium. Therefore, lisinopril is more likely to cause hyperkalemia rather than hypokalemia, making it an unlikely cause.

Choice D rationale

Metoprolol is a beta-blocker that works by blocking the effects of catecholamines on beta-adrenergic receptors. It primarily affects the heart by slowing the heart rate and reducing contractility, thereby lowering blood pressure. It does not directly impact the renal tubules or the handling of potassium, so it is not a direct cause of hypokalemia. Its effect on potassium is considered negligible.